Aging and stationary properties of non-equilibrium symmetrical three-state models

We consider a non-equilibrium three-state model whose dynamics is Markovian and displays the same symmetry as the three-state Potts model, i.e. the transition rates are invariant under the cyclic permutation of the states. Unlike the Potts model, detailed balance is, in general, not satisfied. The aging and the stationary properties of the model defined on a square lattice are obtained by means of large-scale Monte Carlo simulations. We show that the phase diagram presents a critical line, belonging to the three-state Potts universality class, that ends at a point whose universality class is that of the Voter model. Aging is considered on the critical line, at the Voter point and in the ferromagnetic phase.

Exact correlation functions in particle-reaction models with immobile particles

Exact results on particle densities as well as correlators in two models of immobile particles, containing either a single species or else two distinct species, are derived. The models evolve following a descent dynamics through pair annihilation where each particle interacts once at most throughout its entire history. The resulting large number of stationary states leads to a non-vanishing configurational entropy. Our results are established for arbitrary initial conditions and are derived via a generating function method. The single-species model is the dual of the 1D zero-temperature kinetic Ising model with Kimball-Deker-Haake dynamics. In this way, both in finite and semi-infinite chains and also the Bethe lattice can be analysed. The relationship with the random sequential adsorption of dimers and weakly tapped granular materials is discussed.

Theory for correlation functions of processes driven by external colored noise

We study steady-state correlation functions of nonlinear stochastic processes driven by external colored noise. We present a methodology that provides explicit expressions of correlation functions approximating simultaneously short- and long-time regimes. The non-Markov nature is reduced to an effective Markovian formulation, and the nonlinearities are treated systematically by means of double expansions in high and low frequencies. We also derive some exact expressions for the coefficients of these expansions for arbitrary noise by means of a generalization of projection-operator techniques.

Hankinnan strategisen toimintamallin rakentaminen teolliseen pk-yritykseen

Hankinta on yrityksen ulkoisten resurssien hallintaa. Organisaation ulkopuolelta hankitut resurssit muodostavat tavallisesti valtaosan kokonaiskustannuksista, joten hankintojen johtamisella on suuri merkitys yrityksen kannattavuudelle. Hankintatoimella voidaan vaikuttaa kannattavuuteen, kun se toimii yrityksen strategisella tasolla. Tämän työn tavoitteena oli kehittää malli strategisen hankintatoimen rakentamiseen teolliseen pk-yritykseen. Käsiteltäviä osa-alueita olivat hankintojen kategoriointi, hankintaorganisaation rakentaminen sekä strategisten hankintaprosessien määrittäminen ja kuvaaminen. Kuhunkin osa-alueeseen kerättiin teoreettisia ratkaisumalleja, joista kostettiin sovellettava ratkaisu. Teorian pohjalta määritettyä kategorioinnin koostamismallia sekä kategoriapohjaisen hankintaorganisaation rakennustyökalua käytettiin kohdeyrityksen strategisen hankintatoimen rakentamiseen. Prosessiosuudessa määritettiin tehtävien ja vastuiden pohjalta strategiset hankintaprosessit, joista koostettiin tavoiteprosessikuvaukset. Niiden avulla kohdeyritys tai muu mallia soveltava organisaatio voi jalkauttaa toiminnan. Prosesseissa esitetään konkreettisia työkaluja tavoiteasetannan ja mittaroinnin viemiseksi yhtenäisenä strategiatasolta operatiiviseen toimintaan. Lopputuloksena syntyi yhtenäinen, kolmivaiheinen malli strategisen hankintatoimen rakentamiseen.

El efecto de la evaluación del desempeño para alcanzar el rendimiento deseado: un estudio de caso en el hospital santa marta en Samacá-Boyacá. Colombia - enfoque a teoría de restricciones - armonía del ambiente laboral

Este trabajo se centró en enfocar, El efecto de la Evaluación del desempeño para alcanzar el rendimiento deseado, aplicado a Teoría de Restricciones (TOC) encaminándolo a una profundización desde la mirada que permite TOC para la solución de problemas identificando los efectos indeseables del sistema, reconociendo el impacto de la evaluación del desempeño y proponiendo la solución para el mejoramiento a través de la comprensión del problema y diseño de estrategias para el cambio y alcanzar las metas propuestas y entender cuál es el mejor medidor que conduzca a hacer lo que es correcto. Los medidores de desempeño del sector salud en Colombia están basados en el cumplimiento de los parámetros de aseguramiento de la calidad. Los modelos gerenciales utilizados hasta ahora, son basados en el principio de autoridad (alguien manda y alguien obedece) y los parámetros de Evaluación del desempeño son indicadores “fríos” que no necesariamente explican la interacción entre los involucrados. Bajo una entrevista semi-estructurada, se abarcó el tema de valores institucionales, y personales, la importancia de su labor para la buena gestión organizacional y la Evaluación de desempeño aplicada sobre su actividad laboral. Se utilizan los procesos de pensamiento de Teoría de Restricciones (TOC) para identificar la problemática, con herramientas particulares de análisis lógico, conocidas como procesos de pensamiento, para detectar paradigmas que sean responsables de la utilización de los medidores actuales e identificar cuál de estos no permite generar los resultados deseados. De esa manera, permite plantear la solución del conflicto para logar las metas institucionales.

On exact time averages of a massive Poisson particle

In this work we study, under the Stratonovich definition, the problem of the damped oscillatory massive particle subject to a heterogeneous Poisson noise characterized by a rate of events, lambda(t), and a magnitude, Phi, following an exponential distribution. We tackle the problem by performing exact time averages over the noise in a similar way to previous works analysing the problem of the Brownian particle. From this procedure we obtain the long-term equilibrium distributions of position and velocity as well as analytical asymptotic expressions for the injection and dissipation of energy terms. Considerations on the emergence of stochastic resonance in this type of system are also set forth.

Análise espacial do risco de leptospirose canina na Vila Pantanal, Curitiba, Paraná

A leptospirose é uma grave zoonose associada às áreas de baixa renda dos centros urbanos. Embora roedores urbanos sejam considerados como principal reservatório para a leptospirose, o cão também pode desenvolver a doença e se tornar carreador assintomático. O objetivo do presente trabalho foi utilizar a metodologia estatística baseada na teoria de processos pontuais espaciais, buscando identificar a forma como se distribuem os cães sororreagentes para a leptospirose e seus determinantes de risco em uma vila na cidade de Curitiba. A análise do modelo possibilitou identificar as regiões de sobre-risco, onde o risco de soropositividade canina à leptospirose é significativamente maior. A relação significativa do efeito espacial no desenvolvimento da doença, além das variáveis estudadas, revela que não apenas um, mas a ação conjunta dos fatores relacionados ao animal, ao proprietário e ao ambiente influencia o risco maior da doença nos locais de maior efeito espacial. O resultado da análise indica claramente os territórios em maior risco na região da Vila Pantanal, possibilitando o planejamento de ações mais específicas e dirigidas a essas áreas em um contexto de vigilância da saúde.

Cinema hollywoodiano no século XXI: o ritmo em abordagem semiótica e os filmes mais vistos de 2001 a 2010

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Theory of pseudomodes in quantum optical processes

This paper deals with non-Markovian behavior in atomic systems coupled to a structured reservoir of quantum electromagnetic field modes, with particular relevance to atoms interacting with the field in high-Q cavities or photonic band-gap materials. In cases such as the former, we show that the pseudomode theory for single-quantum reservoir excitations can be obtained by applying the Fano diagonalization method to a system in which the atomic transitions are coupled to a discrete set of (cavity) quasimodes, which in turn are coupled to a continuum set of (external) quasimodes with slowly varying coupling constants and continuum mode density. Each pseudomode can be identified with a discrete quasimode, which gives structure to the actual reservoir of true modes via the expressions for the equivalent atom-true mode coupling constants. The quasimode theory enables cases of multiple excitation of the reservoir to now be treated via Markovian master equations for the atom-discrete quasimode system. Applications of the theory to one, two, and many discrete quasimodes are made. For a simple photonic band-gap model, where the reservoir structure is associated with the true mode density rather than the coupling constants, the single quantum excitation case appears to be equivalent to a case with two discrete quasimodes.

Quasimode theory of quantum optical processes in photonic band gap materials

This paper deals with atomic systems coupled to a structured reservoir of quantum EM field modes, with particular relevance to atoms interacting with the field in photonic band gap materials. The case of high Q cavities has been treated elsewhere using Fano diagonalization based on a quasimode approach, showing that the cavity quasimodes are responsible for pseudomodes introduced to treat non-Markovian behaviour. The paper considers a simple model of a photonic band gap case, where the spatially dependent permittivity consists of a constant term plus a small spatially periodic term that leads to a narrow band gap in the spectrum of mode frequencies. Most treatments of photonic band gap materials are based on the true modes, obtained numerically by solving the Helmholtz equation for the actual spatially periodic permittivity. Here the field modes are first treated in terms of a simpler quasimode approach, in which the quasimodes are plane waves associated with the constant permittivity term. Couplings between the quasimodes occur owing to the small periodic term in the permittivity, with selection rules for the coupled modes being related to the reciprocal lattice vectors. This produces a field Hamiltonian in quasimode form. A matrix diagonalization method may be applied to relate true mode annihilation operators to those for quasimodes. The atomic transitions are coupled to all the quasimodes, and the true mode atom-EM field coupling constants (one-photon Rabi frequencies) are related to those for the quasimodes and also expressions are obtained for the true mode density. The results for the one-photon Rabi frequencies differ from those assumed in other work. Expressions for atomic decay rates are obtained using the Fermi Golden rule, although these are valid only well away from the band gaps.

Theory and application of nonlinear wave propagation phenomena in combined reaction/separation processes

Reaction separation processes, reactive distillation, chromatographic reactor, equilibrium theory, nonlinear waves, process control, observer design, asymptoticaly exact input/output-linearization

Theory of mind and cognitive processes in aging and Alzheimer type dementia: a systematic review.

OBJECTIVES: Theory of mind (ToM) performance in aging and dementia of the Alzheimer type (DAT) has been a growing interest of researchers and recently, theoretical trends in ToM development have led to a focus on determining the cognitive skills involved in ToM performance. The aim of the present review is to answer three main questions: How is ToM assessed in aging and DAT? How does ToM performance evolve in aging and DAT? Do cognitive processes influence ToM performance in aging and DAT? METHOD: A systematic review was conducted to provide a targeted overview of recent studies relating ToM performance with cognitive processes in aging and DAT. RESULTS: RESULTS suggest a decrease in ToM performance, more pronounced in complex ToM tasks. Moreover, the review points up the strong involvement of executive functions, especially inhibition, and reasoning skills in ToM task achievement. CONCLUSION: Current data suggest that the structure of ToM tasks itself could lead to poor performance, especially in populations with reduced cognitive abilities.